| /* |
| * ll_map.c |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <string.h> |
| #include <net/if.h> |
| |
| #include "libnetlink.h" |
| #include "ll_map.h" |
| #include "hlist.h" |
| |
| struct ll_cache { |
| struct hlist_node idx_hash; |
| struct hlist_node name_hash; |
| unsigned flags; |
| unsigned index; |
| unsigned short type; |
| char name[IFNAMSIZ]; |
| }; |
| |
| #define IDXMAP_SIZE 1024 |
| static struct hlist_head idx_head[IDXMAP_SIZE]; |
| static struct hlist_head name_head[IDXMAP_SIZE]; |
| |
| static struct ll_cache *ll_get_by_index(unsigned index) |
| { |
| struct hlist_node *n; |
| unsigned h = index & (IDXMAP_SIZE - 1); |
| |
| hlist_for_each(n, &idx_head[h]) { |
| struct ll_cache *im |
| = container_of(n, struct ll_cache, idx_hash); |
| if (im->index == index) |
| return im; |
| } |
| |
| return NULL; |
| } |
| |
| static unsigned namehash(const char *str) |
| { |
| unsigned hash = 5381; |
| |
| while (*str) |
| hash = ((hash << 5) + hash) + *str++; /* hash * 33 + c */ |
| |
| return hash; |
| } |
| |
| static struct ll_cache *ll_get_by_name(const char *name) |
| { |
| struct hlist_node *n; |
| unsigned h = namehash(name) & (IDXMAP_SIZE - 1); |
| |
| hlist_for_each(n, &name_head[h]) { |
| struct ll_cache *im |
| = container_of(n, struct ll_cache, name_hash); |
| |
| if (strncmp(im->name, name, IFNAMSIZ) == 0) |
| return im; |
| } |
| |
| return NULL; |
| } |
| |
| int ll_remember_index(const struct sockaddr_nl *who, |
| struct nlmsghdr *n, void *arg) |
| { |
| unsigned int h; |
| const char *ifname; |
| struct ifinfomsg *ifi = NLMSG_DATA(n); |
| struct ll_cache *im; |
| struct rtattr *tb[IFLA_MAX+1]; |
| |
| if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK) |
| return 0; |
| |
| if (n->nlmsg_len < NLMSG_LENGTH(sizeof(ifi))) |
| return -1; |
| |
| im = ll_get_by_index(ifi->ifi_index); |
| if (n->nlmsg_type == RTM_DELLINK) { |
| if (im) { |
| hlist_del(&im->name_hash); |
| hlist_del(&im->idx_hash); |
| free(im); |
| } |
| return 0; |
| } |
| |
| memset(tb, 0, sizeof(tb)); |
| parse_rtattr(tb, IFLA_MAX, IFLA_RTA(ifi), IFLA_PAYLOAD(n)); |
| ifname = rta_getattr_str(tb[IFLA_IFNAME]); |
| if (ifname == NULL) |
| return 0; |
| |
| if (im) { |
| /* change to existing entry */ |
| if (strcmp(im->name, ifname) != 0) { |
| hlist_del(&im->name_hash); |
| h = namehash(ifname) & (IDXMAP_SIZE - 1); |
| hlist_add_head(&im->name_hash, &name_head[h]); |
| } |
| |
| im->flags = ifi->ifi_flags; |
| return 0; |
| } |
| |
| im = malloc(sizeof(*im)); |
| if (im == NULL) |
| return 0; |
| im->index = ifi->ifi_index; |
| strcpy(im->name, ifname); |
| im->type = ifi->ifi_type; |
| im->flags = ifi->ifi_flags; |
| |
| h = ifi->ifi_index & (IDXMAP_SIZE - 1); |
| hlist_add_head(&im->idx_hash, &idx_head[h]); |
| |
| h = namehash(ifname) & (IDXMAP_SIZE - 1); |
| hlist_add_head(&im->name_hash, &name_head[h]); |
| |
| return 0; |
| } |
| |
| const char *ll_idx_n2a(unsigned idx, char *buf) |
| { |
| const struct ll_cache *im; |
| |
| if (idx == 0) |
| return "*"; |
| |
| im = ll_get_by_index(idx); |
| if (im) |
| return im->name; |
| |
| if (if_indextoname(idx, buf) == NULL) |
| snprintf(buf, IFNAMSIZ, "if%d", idx); |
| |
| return buf; |
| } |
| |
| const char *ll_index_to_name(unsigned idx) |
| { |
| static char nbuf[IFNAMSIZ]; |
| |
| return ll_idx_n2a(idx, nbuf); |
| } |
| |
| int ll_index_to_type(unsigned idx) |
| { |
| const struct ll_cache *im; |
| |
| if (idx == 0) |
| return -1; |
| |
| im = ll_get_by_index(idx); |
| return im ? im->type : -1; |
| } |
| |
| int ll_index_to_flags(unsigned idx) |
| { |
| const struct ll_cache *im; |
| |
| if (idx == 0) |
| return 0; |
| |
| im = ll_get_by_index(idx); |
| return im ? im->flags : -1; |
| } |
| |
| unsigned ll_name_to_index(const char *name) |
| { |
| const struct ll_cache *im; |
| unsigned idx; |
| |
| if (name == NULL) |
| return 0; |
| |
| im = ll_get_by_name(name); |
| if (im) |
| return im->index; |
| |
| idx = if_nametoindex(name); |
| if (idx == 0) |
| sscanf(name, "if%u", &idx); |
| return idx; |
| } |
| |
| void ll_init_map(struct rtnl_handle *rth) |
| { |
| static int initialized; |
| |
| if (initialized) |
| return; |
| |
| if (rtnl_wilddump_request(rth, AF_UNSPEC, RTM_GETLINK) < 0) { |
| perror("Cannot send dump request"); |
| exit(1); |
| } |
| |
| if (rtnl_dump_filter(rth, ll_remember_index, NULL) < 0) { |
| fprintf(stderr, "Dump terminated\n"); |
| exit(1); |
| } |
| |
| initialized = 1; |
| } |